The present invention relates to a fuel supply technique for ensuring excellent combustion of fuel in the internal combustion engine of an automobile.
The present invention relates to a fuel carburetion accelerator for accelerating the carburetion of fuel supplied to an automobile internal combustion engine, which fuel carburetion accelerator can be applied to both the type of combustion engine in which fuel is injected to the air suction ports of each cylinder, and the type of combustion engine in which fuel is injected directly to each cylinder.
To improve the startability of an internal combustion engine, reduce the fuel costs, to purify the exhaust gas and reduce HC gas in purification of the exhaust gas, it is effective to reduce the deposition of fuel on the inner wall surface of an intake manifold by atomizing and vaporizing the fuel spray injected by a fuel injection valve (injector). Further, fuel stabilization is provided by feeding fuel after the atomization and vaporization thereof.
One known way of feeding atomized and vaporized fuel is by installing a fuel injection valve (injector) for use on a supplementary basis mainly when starting the internal combustion engine.
U.S. Pat. No. 5,894,832 discloses a cold start fuel control system comprising a cold start fuel injector, a heater, and an idle speed control valve (hereinafter referred to as an xe2x80x9cISC valvexe2x80x9d). In this system, a swirl is applied to the fuel spray injected by a fuel injection valve that is arranged on the downstream side of the ISC valve of the internal combustion engine so as to be introduced downstream of the air sucked through the ISC valve, thereby promoting a mixing between them. At the same time, the gas mixture for which mixing is promoted is caused to impact against a heater installed on the downstream side of the fuel injection valve, so that the gas mixture is heated and vaporized, thereby reducing the amount of fuel deposited on the inner surface of the intake manifold.
In the above-described system, fuel spray is made to impact on a heater arranged on the downstream side of the fuel injection valve, and vaporization of the fuel spray is promoted by the heat generated by this heater. However, this method is not always sufficient for improvement of fuel spray vaporization.
Such a known type of fuel carburetion accelerator is described in U.S. Pat. No. 5,482,023. This fuel control system has a fuel injection valve, heaters, and an idle speed control valve (ISC valve). For this system, a portion of the air from the ISC valve (namely, a first air current) is mixed with the fuel injected from the fuel injection valve. For this purpose, the hole in the air channel from the ISC valve is provided cyclically around the outlet portion of the fuel injection valve. Immediately after the fuel from the fuel injection valve and the first air current have been mixed, this mixture is fed into an array of cylindrical heaters located downstream at the fuel injection valve. An air channel through which a portion of the air from the ISC valve is to flow is formed on the inner surface of each heater; and, at the outlet of the heater, the air that flows in through this air channel (namely, the second air current) is mixed with the injected fuel that flows in through the inside of the heater. The carburetion of the fuel which has been injected from the fuel injection valve is accelerated during passage through the heater, and, then the carburetion of the fuel is further accelerated when mixed with the second air current at the outlet of the heater.
The conventional system described above has a structure in which the fuel injection valve, the confluent point between the fuel from the fuel injection valve and the first air current, and the mixing chamber provided inside the heaters to mix the fuel and the second air current, are arranged in that order from the upstream side in sequence, and the carburized fuel is directly introduced from the heater outlet into the main air channel.
For a conventional system of such structure, the flow of air along the inner wall surface of the heater becomes nonuniform, and, when the fuel comes into contact with the inner wall surface of the heater, the liquid film tends to become thick in some places and thin in some places. This phenomenon induces the possibility of the fuel being introduced into the main channel without being completely carburized. And this, in turn, poses the problem that, since complete carburetion requires a heater that is greater in capacity, length, and diameter, the power consumption also increases.
One object of the present invention is to improve the efficiency of vaporizing the fuel spray by use of a heater.
To attain the above-stated object, the present invention provides liquid film forming means for converting, into a thin film, the fuel sprayed to the surface of a transfer unit by a fuel injection valve. This means produces a thin layer of liquid fuel film and permits uniform dispersion of fuel, thereby improving the vaporization efficiency.
In this case, the heat transfer surface is formed to have an irregular shape, so that the heat transfer area can be expanded. This allows the heater to be downsized and installed on the throttle body and intake manifold. This also ensures easy installation of it on the engine.
In addition to the above-described means, causing air to act on the fuel spray injected from the fuel injection valve ensures effective atomization of the fuel spray and a smooth feeding of fuel in the downstream direction, and it allows fuel spray to hit the surface of the heat transfer unit uniformly, thereby ensuring formation of a thinner liquid fuel film and a more uniform distribution of the fuel.
Another object of the present invention is to ensure that the fuel comes into the inner wall surface of the heater as uniformly as possible.
A further object of the present invention is to obtain a motor-driven throttle valve equipped with a fuel carburetion accelerator which can be engine-installed with a minimum installation space.
A further object of the present invention is to obtain an air/fuel feeder that can control the flow rates of both air and a carburized fuel.
A further object of the present invention is to obtain a fuel carburetion accelerator that enables at least a portion of its body to be used as an electrode as well.
A further object of the present invention is to ensure more efficient carburetion of the supplied air-fuel mixture inside the cylindrical heater.
A further object of the present invention is to suppress the vaporization of the fuel at the fuel injection valve portion of the fuel carburetion accelerator.
In order to attain at least one of the above-stated objects, the present invention is embodied in the following configurations:
A fuel carburetion accelerator has a fuel injection element for injecting a fuel, a cylindrical inner-walled heater element combined with the fuel injection element to carburize the fuel injected therefrom, a swirling air current supply element installed between the fuel injection element and the heater element to supply a swirling air current from the periphery of the fuel injected from the fuel injection element to the cylindrical inner wall surface of the heater element, and an enclosure that holds the fuel injection element, heater element, and swirling air current supply element. The swirling air current supply element is further equipped with a plurality of blade members for introducing an air current in their radial direction from outside towards the inside and for generating a swirling flow of air around the injected fuel.
A fuel carburetion accelerator has a heater element having a cylindrical inner wall surface for guiding an air-fuel mixture, a swirling air current supply element installed at the end of one side of the heater element to induce a swirling air current along the cylindrical inner wall surface, and a fuel injection element for injecting fuel to the heater element.
A fuel carburetion accelerator has an air guide that has an air inlet port on its outer surface, an air outlet port in its center portion, and an air guide wall provided between the air inlet port and the air outlet port so that air flows from the periphery of the air guide towards the center, a cylindrical heater element having a hole for receiving air from the air guide, and a fuel injection element for injecting fuel to the cylindrical heater element.
A fuel carburetion accelerator has a housing, at one side of which is installed a fuel injection valve and at the other side of which is installed a heater having a cylindrical portion for receiving fuel from the fuel injection valve, an air inlet port provided in the housing to take in air from the outer surface of the housing, a guide wall provided to apply a swirling force to the air taken in from the air inlet port, and an air outlet port formed to supply the heater with the air to which the swirling force has been applied by the guide wall.
A fuel carburetion accelerator has a housing provided with a guide wall to apply a swirling force to air introduced from an air inlet port, a cylindrical heater having a hole for receiving an air current created by the applied swirling force, and a fuel injection valve for supplying fuel to the air current.
A fuel carburetion accelerator is characterized in that one end of the accelerator has an open end upstream at a throttle valve which controls the amount of air to be supplied to a cylinder, and the other end of the accelerator is provided with another air channel connected to a cylindrical heater via an air swirling element, in that the outlet of the heater is connected to an air channel provided downstream at the throttle valve, and in that a fuel injection valve is provided for supplying fuel to the heater.
A motor-driven throttle valve unit is equipped with a fuel carburetion accelerator, characterized in that a fuel injection valve is mounted on an air suction channel enclosure having a motor for a motor-driven throttle valve provided to electrically control the amount of air to be supplied to a cylinder, in that a heater unit for carburizing the fuel injected from the fuel injection port of the fuel injection valve is installed on the air suction channel enclosure, in that the heater unit is equipped with an air inlet port for introducing air from the upstream side of the throttle valve, and with an air-fuel mixture supply port for supplying air and fuel to the air suction channel located downstream at the throttle valve, and in that the air suction channel enclosure has a hole in communication with the air-fuel mixture supply port of the heater unit.
A motor-driven throttle valve unit equipped with a fuel carburetion accelerator is characterized in that a fuel injection valve is mounted on an air suction channel enclosure having a motor for a motor-driven throttle valve provided to electrically control the amount of air to be supplied to a cylinder, in that a heater unit for carburizing the fuel injected from the fuel injection port of the fuel injection valve is installed on the air suction channel enclosure, in that the heater unit is equipped with an air inlet port for introducing air from the upstream side of the throttle valve, and with an air-fuel mixture supply port for supplying air and fuel to the air suction channel located downstream at the throttle valve, and in that the air suction channel enclosure has a hole in communication with the air-fuel mixture supply port of the heater unit.
An air/fuel feeder has a fuel carburetion accelerator equipped with a cylindrical heater unit for carburizing the fuel injected from the fuel injection port of a fuel injection valve, and a motor-driven throttle valve unit for electrically controlling the amount of air to be supplied to a cylinder. The air/fuel feeder is characterized in that the cylindrical heater unit and the motor are arranged so that the central axial line of the heater unit is orthogonal to the rotational axis of the motor, in that the heater unit is equipped with an air inlet port for introducing air from the upstream side of said throttle valve, and with an air-fuel mixture supply port for supplying air and an fuel to the air suction channel located downstream at the throttle valve, and in that the air/fuel feeder itself has a hole which forms the air-fuel mixture supply port of the heater unit.
An air/fuel feeder has a fuel carburetion accelerator equipped with a cylindrical heater unit for carburizing the fuel injected from the fuel injection port of a fuel injection valve, and a motor-driven throttle valve unit for electrically controlling the amount of air to be supplied to a cylinder. The air/fuel feeder is characterized in that the cylindrical heater unit and the motor are arranged so that the central axial line of the heater unit is orthogonal to the rotational axis of the motor, in that the heater unit is equipped with an air inlet port for introducing air from the upstream side of the throttle valve, and with an air-fuel mixture supply port for supplying air and fuel to the air suction channel located downstream at the throttle valve, and in that the air/fuel feeder itself has a hole which forms the air-fuel mixture supply port of the heater unit.
A fuel carburetion accelerator has an air injection valve that injects fuel to the air suction ports of each cylinder, a separate air injection valve connected to a fuel pipeline together with an air injection valve which injects fuel directly to the inside of each cylinder, and a carburizing element for carburizing the fuel injected from air injection valve. The fuel carburetion accelerator is characterized in that at least the fuel pipeline leading to the separate air injection valve adopts a return-type connection scheme.
A fuel carburetion accelerator has a cylindrical heater unit equipped with an inlet port from which a mixture of air and fuel injected from a fuel injection valve is to be taken in, and a portion for heating an air-fuel mixture on the inner wall surface of said cylindrical heater unit, then carburizing the mixture, and discharging the carburized mixture from the outlet hole in the heater unit. The fuel carburetion accelerator is characterized in that a stepped portion is formed towards the inside of the mixture outlet portion of the heater.
More specifically, the following configurations are adopted.
A fuel carburetion accelerator for an internal combustion engine has a first fuel injection valve inside each of its multiple cylinders, and it is constricted in such a manner that a hole is formed halfway in the air suction channel located downstream at the throttle valve of the internal combustion engine, and that a sub-channel having an air inlet port formed at the upstream side of the throttle valve functions as a bypass for the main air suction channel, with the sub-channel having its outlet portion being connected to the air suction channel through a deflecting channel. The fuel carburetion accelerator is characterized in that: it is constructed so that a heater section having a heater which generates heat when powered from outside is provided on the outer surface of the sub-channel, and so that fuel is injected from a second fuel injection valve provided in coaxial relationship with respect to the sub-channel and at the upstream side of the heater section, towards this heater section, in the same direction as that of the flow of air. A mixing chamber is provided at the injection hole portion of the second fuel injection valve; a plurality of air channels formed at equal intervals so as to deviate tangentially from the central axis of the sub-channel are arranged on the outer surface of the mixing chamber: a spiral air introduction channel is positioned along the outer surfaces of the plurality of air channels; and, the spiral air introduction channel is constructed so that the channel area increases at the air inlet side and then decreases progressively.
A fuel carburetion accelerator for an internal combustion engine has a first fuel injection valve inside each of its multiple cylinders, and it is constructed in such a manner that a hole is formed halfway in the air suction channel located downstream at the throttle valve of the internal combustion engine and that a sub-channel having an air inlet port formed at the upstream side of the throttle valve functions as a bypass for the main air suction channel. The fuel carburetion accelerator is characterized in that: it is constructed so that a heater section having a heater which generates heat when powered from outside is provided on the outer surface of the sub-channel and so that a mixing chamber is provided at the upstream side of the heater section. A bypass air channel formed at the upstream side of the throttle valve is positioned in coaxial form with respect to the central axis of the heater section; a second fuel injection valve is provided at a position offset from the central axis of the sub-channel; an inclined plate is provided at the immediate rear of the injection port of the second fuel injection valve to deflect the injected fuel and introduce this fuel into the mixing chamber; and, a plurality of air channels formed at equal intervals so as to deviate tangentially from the central axis of the sub-channel are arranged on the outer surface of the mixing chamber.
A fuel carburetion accelerator for an internal combustion engine has a first fuel injection valve inside each of its multiple cylinders, and it is constructed in such a manner that a hole is formed halfway in the air suction channel located downstream at the throttle valve of the internal combustion engine and that a sub-channel having an air inlet port formed at the upstream side of the throttle valve functions as a bypass for the main air suction channel, with the sub-channel having its outlet portion connected to the air suction channel through a deflecting channel. The fuel carburetion accelerator is characterized in that: it is constructed so that a heater section having a heater which generates heat when powered from outside is provided on the outer surface of the sub-channel and so that fuel is injected from a second fuel injection valve provided in coaxial relationship with respect to the sub-channel and downstream at the heater section, towards the mixing chamber at the upstream side of the heater section, in the opposite direction so as to collide with the flow of air. A plurality of air channels formed at equal intervals so as to deviate tangentially from the central axis of the sub-channel are arranged on the outer surface of the mixing chamber; a spiral air introduction channel is positioned along the outer surfaces of the plurality of air channels; and the spiral air introduction channel is constructed so that the channel area increases at the air inlet side and then decreases progressively.
A fuel carburetion accelerator has an air swirling element for receiving air from an air channel provided at the upstream side of a throttle valve which controls the amount of air to be supplied to a cylinder, a cylindrical heater unit for acquiring the air to which swirling force has been applied by the air swirling element, and a fuel injection valve for supplying fuel to said cylindrical heater unit. The fuel carburetion accelerator is characterized in that the air-fuel mixture outlet hole in the cylindrical heater unit is connected to a surge tank provided downstream of the throttle valve.